docs: def browser(browser_name='xdg-open'):
  
      """Create a browse-directory function."""
  
      if not browser_name:
          return None
      argv = shlex.split(browser_name)
      executable = find_executable(argv[0])
      if executable is None:
          # Why not raise an exception? -I think it is more convenient (for
          # end users) to have a reasonable default, without enforcing it.
          logging.getLogger(__name__).warn(
              _("Can't find file browser: {0!r}. "
                "You may want to change the value for the '-f' option.",
                browser_name))
          return None
  
      def browse(path):
          return subprocess.Popen(argv + [path])
  
      return browse